Heat exchanger



June 11, 1935. J. BENZINGER HEAT EXCHANGER Filed April 11, 1954 s Sheets-Sheet 1 VAVA INVENTOR fl/s ATTORNEYS June 11, 1935. J BENZINGER HEAT EXCHANGER Filed April 11,' 1934 3 Sheets-Shae; 2

INVENTOR I WyM If TTORNEYS June 11, 1935. J. BENZINGER HEAT EXCHANGE R Filed April 11, 1934 3 Sheets-Sheet 3 INVENTOR BY ?n-voi 3M, 31% M w: ATTORNEYS Patented June 11, 1935 HEAT EXCHANGER Julius Benzinger, Queens Village, N. Y., assignor to The Griscom-Russell Company, New York, N. Y., a corporation of Delaware Application April 11, 1934, Serial No. 720,017

16 Claims.

This invention relates to a combined condenser and sub-cooler. The apparatus is adapted to do all work in which it is desired to condense vapor and cool the condensate, but it is particularly for use in connection with oil refining.

In the operation of a condenser, it is desirable that thecondensate at any point shall not be at a higher temperature than the vapors in contact therewith. Generally, that condition will be substantially maintained as long as the vapor and condensate remain closely associated in numerous paths and in a heat-exchanging relation. But if, as in the usual type of multi-pass construction, the vapor and condensate are allowed to separate at the end of each pass, there is a tendency for the condensate, being of concentrated volume, to thereafter flow along in con: tact with only a small part of the cooling surfaces of the condenser. As a result, the condensate temperature at the end of a given pass of the apparatus tends to be higher than the vapor temperature at the same point. It is an object of the present invention to provide a condenser in which the flowing condensate is exposed to an increased area of cooling surface, so as to maintain its temperature substantially as low as, or lower than, that of the vapor in contact therewith.

A further problem frequently encountered in the operation of condensers of the ordinary type, is the ineificient utilization of cooling surfaces in certain parts of the apparatus. In certain applications peculiar conditions of temperature, pressure, volume, or degree of saturation of the vapor may require particular combinations of cooling area and vapor velocities for efficient functioning. For example, it is not unusual for most of theoondensation to take place in the first passes of thecondenser, so that only lean, dead gases flow through the final passes of the apparatus; at the same time, with the usual forms of construction, the condensate at the outlet of the condenser is only slightly sub-cooled. It is an object of the present invention to provide a combination condenser and sub-cooler in which all cooling surfaces will be utilized to the best advantage; whereby the eficiency of the apparatus may be improved, and the condensate substantially sub-cooled.

A further object is to provide such apparatus in which the means for proportioning the condensing and sub-cooling areas may readily be changed to meet a change in conditions of operation.

Another object is to provide in connection with such apparatus means to facilitate the drainage of condensate from the apparatus in case of shutdown.

In general, the objects of my invention may be obtained by condensing apparatus having a pair of headers, a plurality of tubes interconnecting said headers, means for supplying condensable vapor to the apparatus, and means for bringing the flowing condensate into contact with a large area of cooling surface. take a variety of forms. It may be a. dam-like element by which a. large part of the cooling sur face may be flooded with condensate. In a multipass condenser of the atmospheric type, such dam elements are most conveniently associated with the headers, and are designed to divide the flow of condensate among a large number of the lower tubes in at least one pass. It is generally desirable to provide drainage means in connection with such dam elements. 2 An alternative form of means for controlling the amount of cooling surface eifective upon the condensate, is the subdivision of the flow of condensate from any pass into a plurality of isolated, vertically-spaced paths of flow in the following pass. I V

The various objects of my invention will be more apparent upon considering the following detailed description of certain embodiments thereof. This description is to be taken in conjunc- 36 tion with the accompanying drawings, in which: i Fig. l is a vertical section view of a condenser embodying my invention;

Fig. 2 is a horizontal section view taken along the plane 22 of Fig. 1 showing details of construction;

Fig. 3 is a vertical section view taken along. the plane 3-3 of Fig. 6, and showing another embodiment of my invention;

Fig. 4 is a vertical section view of the lower part 49 of a header of Fig. 3, taken along the plane t-l of Fig. 6, and showing details of construction;

Fig. 5 is a transverse view of the inside face of the part of the cover plate shown in Fig. 4;

Fig. 6 is a horizontal section view taken along the plane 6 6 of Fig. 4, showing details of construction; and

Fig. 7 is a vertical section view showing'another embodiment of my invention.

1 Similar numerals refer to similar parts throughout the several figures of the drawings. One embodiment of my invention, illustrated in Fig. 1 of the accompanying drawings, comprises a plurality of tubes it, the ends of said tubes being suitably mounted in the tube sheet castings i l and The latter means may 10 vided with suitable openings vided with suitable means I2. Casting l i is shown with both an inlet connection 2i and an outlet connection 22. Both castings HI and i2 have section separators 23 for providing multi-pass flow through the tubes.

Detachably secured to the casting M by. any suitable means, such as the studs 25, are the dam plate 115 and the cover plate 93, this assembly constituting a header. In the same manner the dam plate it and cover plate it are secured to the casting l2, forming the. other header. The cover plates are prbvided with section separators 28 corresponding to separators 23 on the tube sheet castings, alternate separators 28 being pro- Zil to allow flow be- The cover plates may also be profor lifting the contween passes.

denser, such as eyelets 2t.

Dam plates is and it are disposed between the cover plates and the tube sheet castings. In this embodiment, they are metallic sheets having apere tures designed to allow the free flow of vapor and condensate at the inlet of a pass, but to prevent the discharge of condensate from one pass into the next except by flow over the dam. In Fig. l, the dam plates are shown clamped between the cover plates and the tube sheet castings by means of the studs 25. An alternative construction is to cast the dam elements integral with the cover plates.

Drainage plugs ill pass throughthreaded holes in the cover plate and engage the drain ports ill at the base or" each damelement. Additional plugs may also be provided at various levels on v each dam element for purposes pointed out below.

The operation of the embodiment illustrated by Fig. 1 is as follows:

The path of flow is indicated by arrows on the figure. When operation of the unit is begun, vapor, either alone or with some liquid, enters the condenser through the inlet connection 28. The vapor passes through the upper tubes of the first pass and is cooled by the transmission of heat through the tubes to the external cooling medium. Condensate forming in the first pass drops into the space 2! at the end of the pass. The liquid entering the inlet 28 falls to the bottom of the inlet space, flows through the lowermost tubes of the pass where it is somewhat cooled in the same manner as the vapor; whence it passes into the space Zl behind the dam element. Since there is no liquid outlet from the pass except by flow over the dam edge 2 9, the

liquid and condensate accumulate to that level, flooding all thetubes of the first pass below that level. After the level of the liquid reaches the dam edge 29, it is apparent that the liquid enter-' ing through the inlet M will flow through the flooded tubes and over the dam at the same total it enters the apparatus. The dam element-isthus seen to eifect an increase in the amount of cooling surface in contact with the liquid, and to cause a slower rate of flow through each tube flooded. The combined effect of these features is to sub-cool the liquid the desired amount. It is apparent that the total flow over the dam is made up of whatever liquid may enter the inlet, increased by the amount of condensate forming in the upper tubes of the pass and dropping into' the space 21. This entire overflow, together with uncondensed vapor from the upper tubes, passes through the opening 24 to the next pass, where the same process is repeated. So also in each pass, until the lean vapor and cooled condensate pass through the outlet connection 22.

The level of the overflow openings in the dam 1 many factors.

plates depends on the application for which the apparatus is to be used and is determined by For certain applications, it may be necessary to provide difierent proportions of cooling area for vapor and condensate than for other applications. The eficient usefulness of a given apparatus may, therefore, be greatly extended by providing several sets of dam plates which differ in the number of dam elements utilized, or in the level of the dam edges. Or, if desired, wide flexibility can be had by providing a plurality of drainage ports similar to ill, but arranged at difierent levels in each dam element; the efiective overflow level of each dam element could then be varied by opening or closing these ports by means of the plugs El from the outside of the apparatus, and without interrupting operation. If no sub-cooling is desired, all drainage ports may be openedo'r both dam plates may be entirely removed, and the apparatus operated as a standard condenser.

When the condenser is shut down for any considerable length of time, or when the cover plate is to be detached for any purpose, it is desirable that any liquid held behind the dam elements should be drained oil. To do this, it is only necessary to unscrew the plugs it until the cotter pins or similar devices it strike the cover plate, indicating to the operator that the drainage ports M are fully open.

The apparatus shown in Fig. i has a dam element in the first pass. Such a design is particu- Where only vapor enters the first pass, there would ordinarily be little necessity for immediately sub-cooling the condensate in the first pass; hence, the dam elements in the first pass or passes may be omitted. Such a construction is shown in Fig. 3, which also shows one way in which the dam elements may be constructed integral with the cover plate. 7

Though the elements of the embodiment shown in Fig. 3 are fundamentally the same as those of the embodiment previously described, some of the structural details are quite different. The principal differences are in the construction of the cover plates 33 and 34 of Fig. 3. The integral construction of the cover plate and dam elements is effectively accomplished in a unique manner further illustrated by Figs. 4, 5 and 6. The built-in dam elements 35 correspond functionally to the apertures in the dam plates I5 and it of Fig. 1, and operate in a similar manner. Thus, condensate collects in the space 21 behind the dam elements 35, and floods the tubes which communicate with that space. The path of flow, indicated by arrows on the figures, is through the openings 36 at the sides of the cover plate, over the dam elements 35, down the center channel 31! to the inlet opening 38 of the next pass. Flexibility in this embodiment may be obtained by providing several sets of cover plates having different overflow levels, or by using other means to raise or lower the effective level of the dam elements 35. though for simplicity no draina Consequently,

means are shown in connection with Fig. 3, it is apparent that means similar to those which have been previously described are here applicable.

Figure 7 illustrates a means by which is effected the contact of the condensate with an increased cooling area without the use of dam elements. In this embodiment, there are provided in the headers auxiliary return bonnets which divide the flow of condensate into isolated parallel paths as indicated by the arrows on the figure.

These auxiliary return bonnets may be formed by providing additional separators 23' on the tube sheet casting cooperating with the inner cover plates 40. These inner cover plates are so situated within the header that they do not impede the flow of condensate and vapor from the tubes not included within. the auxiliary return bonnet. The inner cover plates may be constructed integral with the main cover plates l3 and I4 or they may be made detachable and held in position by any suitable means, as by attachment to either the tube sheet castirfig or the cover plate, or by itated.

Though the embodiment of Fig. 7 shows both the vapor and the condensate confined to the same isolated paths, it is apparent that there will usually be no objection to allowing all the vapors to mix together at the beginning of each pass.

. Also, it is not essential that the separate paths of condensate flow shall be continuous through several passes; for it is generally immaterial in what way the condensate is collected at the end of a pass, so long as it is divided into a plurality of vertically spaced paths upon entering the following pass.

limited to the exact forms of construction herein disclosed, for various modifications thereof are possible without departing from the spirit of my invention. For instance, the number of passes,

their arrangement, and proportions are variable within wide limits. Also, my invention may be applied to condensers of the enclosed type as well as to those of the atmospheric type illustrated.

I claim:

1. Apparatus of .the type described, comprising a pair' of headers, a plurality of tubes interconnecting said headers and providing cooling surface, means for supplying condensible vapor to said tubes, and means for controlling the flow of condensate through said tubes to subject the same to varying areas of cooling surface as it progresses, to maintain the temperature of the condensate substantially as low as that of the vapor in contact therewith.

2. Apparatus of the type described, comprising a pair of headers, a plurality of tubes interconnecting said headers and providing cooling surface, means for supplying condensible vapor to said tubes, and means for directing the flow of condensate into contact with a progressively Thus, instead of flowing It is to be understood that my invention is not increasing area of cooling surface to maintain the temperature 'of the condensate substantially as low as that of the vapor in contact therewith.

, 3. Apparatus of the type described, comprising a pair of headers, a plurality of tubes interconnecting said headers, means for supplying condensible vapor to the tubes, and means for dividing the flow of condensate in a part of the condenser into a plurality of vertically-spaced paths through the tubes, and in another part of the condenser into a larger number of vertically spaced paths through the tubes.

4. Apparatus of the type described, comprising a pair of headers provided with separators for multi-pass operation, a plurality of tubes interconnecting said headers, means for supplying condensible vapor to the tubes, and means associated with at least one pass for controlling the number of tubes in that pass through which thecondensate from preceding passes shall flow.

5. Apparatus of the type described; comprising a pair of headers provided with separators for multi-pass operation, a plurality of tubes interconnecting said headers, means for supplying condensible vapor to the tubes, and means associated with at least one pass for dividing the flow of condensate from preceding passes among a plurality of vertically-spaced tubes in said 6. Apparatus of the type described, comprising a pair of headers, a plurality of tubes interconnecting said headers, means associated with said headers for providing multi-pass flow of fluid through said tubes, means for supplying condensible vapor to the tubes, and dam means for flooding a predetermined number of tubes in any .pass with condensate from the preceding passes.

7. Apparatus of the type described, comprising a pair of headers, a plurality of tubes interconnecting said headers, means associated with said headers for providing multi-pass flow of fluid through said tubes, means for supplying condensible vapor to the tubes,,and dam means associated with at least one pass for dividing the 'flow of condensate from preceding passes among a plurality of tubes at diiferent vertical levels in said pass. I

8. In apparatus of the typedescribed, a. header comprising a cover plate, a tube sheet. having a plurality of vertically spaced tubes secured thereto, means for supplying condensible vapor to said tubes, fluid tight separators for providing multipass flow of fluid through said tubes, and a dam plate detachably interposed between said tube sheet and cover plate for causing condensateto flow through some of said tubes and for directingv uncondensed vapor into other tubes at a lower level.

9. In apparatus of the type described, a header comprising a cover plate, a tube sheet having'a plurality of vertically spaced tubes secured thereto, means for supplying condensible vapor to said tubes, fluid-tight separators for providing multipass flow of fluid through said tubes, and a dam plate detachably interposed between said tube sheet and cover plate, said dam plate comprising a metallic sheet having an aperture associated with each pass, at least'one of said apertures being so positioned above certain of said tubes that its lower edge may serve as a dam to the flow of condensate whereby the condensate is caused to flow through a number of said tubes, and uncon- 'er comprising a tube sheet having a plurality of vertically spaced tubes secured thereto, means .for supplying condensible vapor to said tubes,

fluid tight separators for providing multi-pass flow of fluid through said tubes, and a cover plate provided with dam means integral with said covrality of isolated paths at different vertical levels 'ing a pair of headers ,for multi-pass operation,

in said pass.

12. Apparatus of the type described, comprisprovided with separators a plurality of tubes interconnecting said headers, means for supplying condensible ,vapor to the tubes, and means comprising an auxiliary return bonnet for effecting the flow of condensate from one pass through a pluralityof vertically-spaced tubes in the succeeding pass. 7

13. Apparatus of the type described, comprising a pair of headers provided with separators for multi-pass operation, a plurality of tubes interconnecting said headers, means for supplying condensible vapor to the tubes, and means comprising anauxiliary return bonnet to isolate the condensate flowing from a part of the tubes of into the upper tubes of the succeeding pass,

aooaseo one pass, and direct it through tubes of the suc} ceeding pass separate from the rest of the condensate. is. Apparatus of the type described, comprising a pair of headers provided with separators for multi-pass operation, a plurality of tubes interconnecting said headers, means for supplying condensible vapor to the tubes, and at least one auxiliary return bonnet for directing the flow of the condensate from the lower tubes of one pass said auxiliary return bonnet comprising a pair of separators and. an inner cover plate.

15. Apparatus of the type described, comprising a pair of headers provided with separators for multi-pass operation, a plurality of tubes interconnecting said headers, means for supplying condensible vapor to saidtubes, dam means for flooding a part of the tubes of at least one pass with condensate from preceding passes, and drainage means accessible from the exterior of the condenser for draining such condensate from the flooded parts.

16. Apparatus of the'type described, comprising a pair of headers, a plurality of tubes interconnecting said headers, dam-means associated with said headers, and drainage means comprising a plug, one end exterior of the condenser and the other end of which removably engages a drain port through and at the base of said dam means.

- JULIUS .BENZINGER.

ofwhich is accessible on the 

